- Innate (non-specific) and Acquired (specific)
Phagocytosis K cells
Physical Barrier NK cells
- Innate Immunity
- need no previous contact
- Physical barriers, fever, phagocytosis, inflammation
- Acquired Immunity
- learned response
- process of recognition, learning, memory & self-discrimination
- Fundamentals of Specific Immunity
- Lymphocytes => cells that mediate immunity
WBCís (35% of WBC population)
T-lymphocytes, B-lymphocytes, third population
Antibodies Cell-cell combat
- T lymphocytes
- T-cells attack pathogens themselves
- B lymphocytes
- produce antibodies
- react to a specific antigen
- Y-shaped protein molecules
IgM - produced first
IgG - main Ab in blood
IgE - Allergies
IgA - saliva, breast milk
IgD - major surface receptor on B lymphocytes
- Third population cells (null cells)
- cell killing
- K- cells
- NK- cells
D) The Immune Response
- T-cells & Cell-Mediated Immunity
a) TH => helper T-cells
- stimulate response of both T-cells & B-cells
- activate B-cells to make Abís
- Ts => suppressor T-cells
- inhibit T-cell & B-cell activity
- moderate immune response
- Tc => cytotoxic T-cells
- responsible for cell-mediated immunity
- direct physical/chemical attack of Ag
- B-cells & Ab-mediated immunity
- B-cell Activation
- TH cells, Memory B-cells & Plasma cells
TC cells Specific Defenses Abís
Activation TH cells Activation
of T-cells of B-cells
Produce memory Produce memory B-cells
TC cells & TC cells & plasma cells
- HIV (Human Immunodeficiency Virus)
- HIV-1 and HIV-2
- HIV-1 => More virulent strain; More recent appearance.
- HIV-2 => Less virulent strain; Possibly trace back 100 years
May afford some protection against HIV-1 infection.
- Evolution of Virulence
- pathogen => any organism that causes disease in humans
- virulence => ability of a pathogen to overcome the host defenses
III) AIDS (Acquired Immune Deficiency Syndrome)
A) Lifecycle of HIV (Human immunodefieciency virus)
gp120 bind to TH cells at CD4
Viral core protein & RNA brought into TH cells
RNA codes for viral DNA Reverse
Viral DNA merges with host DNA
New Virus Synthesis AZT
Repetition of infection sequence
- latent period => HIV present but inactive (may not really exist)
b) Acute phase (30-50%)
d) Chronic phase
e) Crisis phase
C) Treatment and Current Research
- AIDS cocktail
DImpact of TH cells
Decrease in TH cells
Impaired Impaired Impaired
Ab production inflammatory cellular
Increased rate & Tumor Growth
severity of infection
- Routes of transmission (Risk Behaviors)
- Public Health and Public Policy
- HIV testing
- Guidelines for handling blood
- Access to healthcare
- Educational campaigns
- United States vs Worldwide patterns of infection
Assignment: HIV and AIDS 20 points
- What is the difference between innate and acquired immunity?
- Give a few examples of innate immunities.
- What is the difference between cell-mediated and antibody-mediated immunity?
- What is the purpose of NK cells?
- Why are helper T-cells so important to both cell-mediated and Ab-mediated immunity?
- What are antibodies and how do they work?
- How do T-cells work?
- Why can you acquire resistance to some pathogens but not to others?
- What causes AIDS?
- Describe the lifecycle of HIV.
- Describe the disease progress of AIDS.
- What is meant by the latent period of infection of AIDS?
- Describe some current treatment methods of AIDS.
- Why does infection with HIV-2 seem to protect against infection with HIV-1.
- What is the difference between HIV-1 and HIV-2
- Describe the difference between high-risk, low-risk and no-risk behavior.
- How has public policy helped to decrease the infection rate of HIV?
- Describe the difference in patterns of infection in the U.S. and other places in the world.